It happened 50 years ago this month – just after my father resigned from Macmillan’s government, and before the assassination of JFK – and, though it never made the headlines, it transformed my world for ever. From a small Highland burn, on crude worm tackle, I hoicked my first troutling into the heather.

Since then, I have spent thousands of days peering into the water in more than 35 different countries, seeking out everything from minnows to mangrove snappers, and I have loved almost every moment of it.

I was supremely lucky. Apprenticed to a venerable uncle, who had been an air ace in the First World War and was a fishing fanatic, I had a privileged introduction to the sport; in his old age, the roles were reversed, and I was able to put the net under his last- ever fish when he was 90.

But these days, fewer young people are coming into angling, traditional mentors seem thin on the ground, and leisure time is increasingly catered for by the great indoors. Staring at screens rather than streams, a whole generation is in danger of becoming – in Woody Allen’s fine phrase – “at two with nature”.

Those of us brought up on the water (be it canal, pier or chalk stream) believe that fishing is not just fun, it can be good for you. It offers emotional refreshment, and a particular interface with the natural world.

This is hardly a new idea: back in the 15th century, Dame Juliana Berners was advocating its wholesomeness, and it has historically been an activity associated with stealth, dexterity, lateral thinking, alertness, persistence, self-sufficiency, and a special cast of mind to cope with frequent disappointment (although I admit it has its fair share of crackpots, too).

A potentially democratic pursuit, it often spans differences in geography, background and the generation gap. Izaak Walton’s mentor, the diplomat Sir Henry Wotton, wrote that angling was ''a calmer of unquiet thoughts, a moderator of passions, a procurer of contentedness”.

More recently, Roger Daltrey pronounced it was ''much better than a Mogadon”.

Down a chalky lane in the green depths of Hampshire, one particular organisation is trying to calm the unquiet thoughts of teenagers by introducing them to an experience that combines recreation with education.

Fishing For Schools (F4S) is a charitable trust run by the enterprising Countryside Alliance (CA), and is effectively the brainchild of Charles Jardine (once known as ''the David Beckham of the fishing world”.)

It is aimed at students in secondary education, especially those with learning difficulties, physical disabilities and a spectrum of special needs.

Working alongside teachers in and out of the classroom, it explores core curricular subjects (maths, natural science, English) through the medium of angling and its range of associated skills – social, practical and interactive. It fills the gap between fun and academia.

From the start, as Jardine and his colleague Rob Doyle greet students individually, there’s a distinctive atmosphere to this gathering – welcoming, industrious, enthusiastic.

Teachers, carers and chaperones bustle about the lakeside as teenagers from five different schools arrived, some of them in wheelchairs. A couple of likely lads are already pointing out trout cruising the clear waters nearby.

Jardine sets the tone by announcing, ''We have some of the best instructors in the UK, but they’re only as good as the questions you ask them.’’ I have known him since 1980, when he was a young guide, and played with the rock band The Rats.

Since then he has become our renaissance man of angling – acclaimed artist, author, journalist (like me, a former fishing columnist of this newspaper) and internationally renowned casting demonstrator.

This most modest of men is the leading light of F4S and is hugely popular, with a true talent for getting people to do things for the cause. There is no shortage of volunteers; what they need now is some more money.

What distinguishes F4S from certain similar initiatives is the degree of classroom involvement – its qualified instructors effectively complement formal education.

Jardine visited 34 schools last year, and to date around 2,500 students (mainstream and otherwise) have participated in various programmes across England and Wales. ''It’s about energising young people,” he says, ''raising the aspirations of an audience who are often disfranchised, or at risk. Often we are seen as the catalyst to learning.”

''And,’’ adds Barney White-Spunner, executive chairman of the CA, ''it gives them the chance to understand their rural heritage, to see how nature works, and introduces them to the wonderful variety of our ecosystem.’’

They fish for everything – ''Dabs and flounders in the Medway docks, golden mullet on Rosily beach. Believe me,” says Jardine, ''there are few trout to be found in Moss Side.’’

At Meon Springs, I attach myself to a group of nine boys and girls from Midhurst Rother College, a local academy. Only one has ever tried fishing before, though their teacher Paul Thompson is keen: ''It’s therapeutic, isn’t it? And there isn’t really an age divide.’’

First stop is bug hunting with entomologist Dr Cyril Bennett; he has them chasing little swimming insects with a pipette, then examining them under his microscope. ''That’s so cool,’’ comes one early response.

''You can’t force them to learn,’’ says Bennett, ''You can just open doors.” I wish I’d been able to hold students that spellbound when I was a teacher.

Next comes a lesson in how to construct artificial flies – in this case a damsel nymph, combining marabou stork feathers, tiny beads and half-hitched thread. Levels of concentration become intense, with all nine producing creditable results.

While others try pole-fishing or float-making, our group heads down to the lake for a fly-casting session, initially using a scrap of wool for safety. But some youngsters opt to ''go live” with a hook, and 11-year-old Liam Griffiths is soon attached to a 2lb rainbow, which he decides to kill and keep. It is carried up to the kitchen area in collective triumph.

Restaurateur Richard Abson quickly has the attention of his audience. To cries of ''Ugh”, he slices out the guts and stylishly dishes up some fried fillets with oatmeal and pesto, thus completing the essential idea of the fishing circuit.

''More interesting than what we do in biology,” reckons one convert, appreciatively tucking into a goujon.

Despite several million British devotees, angling has some detractors on ethical grounds; but – notably – the F4S projects have met with no political or educational opposition. Rather, the response has been so positive that now they are having to turn away new schools.

Although delivered free, each course of four sessions costs the charity £1,419 (covering equipment, venues, and administration), and in order to guarantee 30 such courses annually for the next three years a campaign is being launched this month to raise a total of £138,960.

Having seen the dedication and excellence of their operation at first hand, I feel convinced they deserve our support.

As we pack up our things and prepare to set off from the riverbank, I ask Thompson if he feels the day has been a success. ''That is an understatement,” he says, as his group receive their personal certificates.

I for one am going to send Fishing For Schools a donation, to help open a few more of those doors of opportunity, and perhaps to procure a little extra contentedness. I hope you will consider doing so too.

David Profumo is fishing correspondent for 'Country Life' magazine.

Further information about Fishing For Schools from Charlotte Cooper (charlotte-cooper@countryside-alliance.org); or for donations or sponsorship contact Lucy Gibbs (020 7840 9298; lucy-gibbs@countryside-alliance.org) or write to F4S, Old Town Hall, 367 Kennington Road, London SE11 4PT.